Concrete form clamp



June 14, 1932. A. B. WILSON CONCRETE FORM CLAMP 2 Sheets-Sheet l 0672 Z07 ZU/VZZJWZA F'led Aug. 1, 1929 June 14, 1932. A, w soN CONCRETE FORM CLAMP Filed Aug. 1, 1929 2 Sheets-Sheet 2 Ji /U672? a/Z622 E. ZgzyZaava Patented June 14, 1932 IIED STATES ALLEN B. WILSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO ACME STEEL COMPANY, OF CHICAGO, ELLINOIS, A CORPORATION OF ILLINOIS CONCRETE FORM CLAMP Application filed August 1, 1828.

ers which are employed for uniting the opposite walls of forms in which concrete or other plastic material is molded and allowed to harden. In the building of concrete walls, bridge abutments, and various other structures, it is common practice to form surrounding walls constructed usually of wood which define the boundaries of the wall or other structure to be built and which confine the plastic concrete or other semi-fluid material which is subsequently poured therein to take the shape imparted to it by the form. The walls of these forms are often of considerable extent and it is the usual practice to tie them together at intervals in order to prevent them from spreading due to the weight or impact of the concrete or other material which is poured in between them. The devices which have heretofore been employed for securing the ends of the metal straps or other binders which are stretched between the opposite walls of concrete forms and the like have not been convenient to manipulate and have usually required the operation of a number of parts or attachments for securing them to the straps and for securing them to the concrete forms. A further disadvantage of these prior devices is that they have usually necessitated the employment therewith of an auxiliary device for stretching the strap taut before applying the clamp thereto. The principal object of the present invention is to provide an improved concrete form clamp which serves as a securing device and also as a stretching tool. A further object of the in vention is to provide a form clamp embodying an improved device for automatically gripping the strap or other binder which passes through the form. Still another object of the invention is to provide an improved form clamp embodying integral means by which it is secured to the wall of the form or other support. A further object of the invention is to provide concrete form clamps so constructed that the tension Serial No. 382,603.

in the strap passing through the form tends automatically to establish and maintain the connection of the clamp with the timber or other support to which it is applied. Other objects relate to various features of construction and arrangement which will appear more fully hereinafter.

The nature of the invention will be understood from the following specification taken with the accompanying drawings in which two embodiments of the invention are illustrated. In the drawings,

Figure 1 shows a perspective view of a portion of a concrete form with a strap extending between the opposite walls thereof and secured to the supporting structure of these walls by means of the improved clamp of the present invention;

Fig. 2 shows a vertical section through the structure illustrated in Fig. 1, illustrating the arrangement of the improved clamp at both ends of the strap which extends through and between the opposite walls of the form;

Fig. 3 is a perspective view of the improved clamp shown in Figs. 1 and 2;

Fig. 4 is an enlarged sectional view similar to that of the left hand side of Fig. 2, showing the position of the form clamp after the strap has been applied thereto and illustrating the manner of employing the clamp in tightening the strap preliminary to securing the clamp on a timber of the wall structure;

Fig. 5 is a sectional view similar to that of Fig. 4 showing the position of the clamp after the strap has been stretched taut and the clamp has been passd into final position on the timber of the wall structure Fig. 6 is a perspective view of a modified form of clamp embodying the features of the present invention;

Fig. 7 is a sectional view through one side of a concrete form wall showing the application of the form of clamp illustrated in Fig. 6 during the process of stretching the strap taut; and

Fig. 8 is a sectional view similar to that of Fig. 7 showing the modified form of clamp after it has been passed to its final position with the spikes thereof engaging the timber to which the clamp is applied.

* tion of the device.

The form of the invention shown in Figs. 1

to 5, inclusive is illustrated as applied to a concrete form having two upwardly extending parallel walls 11 each formed of a series of horizontal boards 12 nailed or otherwise secured to upright timbers 18. The upright timbers 13 are arranged in parallel relation and are reenforced and spaced apart by other horizontally extending timbers 14 which are preferably rectangular in cross section according to the usual practice in con structing forms of this kind. The concrete or other material to be molded is filled into the space between the walls 11 and, for the purpose of preventing the separation of these walls when the concrete is poured therein, they are connected together at intervals by means of sheet metal straps or binders 15, one of which is shown in Figs. 1 and 2, although itwill be-understood that these are distributed at intervals throughout the area of the concrete form. The strap 15 passes through apertures 16 which are formed in the boards 12 of the walls 11 and these apertures are preferably located in'proximity to the timbers 14 on opposite sides of the wall or form so that these timbers may be utilized in securing the form clamps 17 which constitute the improvement of the present invention. I The form clamp 17 is preferably formed of steel having a slight resiliency and it comprises a bar or arm 17 which is reversely bent to form a tongue or flange l7 spaced slightly from the body of the bar 17 as shown at 17 in order to accommodate the thickness of the strap 15. A slot 17 is provided in the curved portion which unites the body 17 with the flange or tongue 17 and this slotpermits the end of the strap 15 to be inserted therethrough and through the space 17, after which the extremity 15 of the strap is reversely bent to lie in contact with the outer surface of the flange or tongue 17', thereby establishing an interlocking connection between the strap and the form clamp which permits the strap to be stretched and held taut by the subsequent manipulation of the clamp. The arm or bar 17 is formed integrally with another arm or bar 17 which extends at right angles to the part 17 on the side thereof opposite the flange or tongue 17 and which is preferably provided with a longitudinal slot 17 extending throughout the major portion of its length to increase the resiliency of this por- The end of the part 17 e is bent as shown at 17 to extend parallel to the arm 17 and the end of this flange 17 is formed integrally with an inwardly directed spike 17 formed by bending inwardly and sharpening the extremity of the part 17 The clamp thus has a general rightangular form with means at one end for securing the strap thereto and with means at the other end for securing the clamp to a timber of the wall to which it is applied.

In the operation of applying the clamp and stretching the strap taut, one end of the strap is first secured at one side of the form 10 by attaching that end of the strap to one of the timbers 14 either by nailing or by the use of the clamp as shown in Figs. 1 and 2. If the clamp is employed, the end of the strap is interlocked with the flange 17 of the clamp and then the clamp is placed around the timber 14 and the spike 17" of the clamp is driven into the timber suflicently to hold the clamp in place. Then the strap, which is threaded through the openings 16 of the opposite walls 11, is applied to the end of another clamp 17 as shown in Fig. 4, the strap being gripped at a point sufficiently far removed from the end thereof to cause the bar 17 of the clamp to assume an inclined position over the upper corner 14 of the timber, thus permitting the clamp to be moved clownwardly and inwardly toward the position shown in Fig. 5 to stretch the strap taut. As the strap is stretched taut, the clamp 17 is moved downwardly to the position shown by dotted lines at 18 and the part 17 is pushed inwardly with the spike 17 in contact with the under side of the timber 14, thus causing the part 17 to bend as illustrated by the dotted position thereof. When the clamp has been moved inwardly to a sufficient extent, the spike 17 snaps upwardly behind the inner face 14 of the timber as the part 17 straightens out and then the clamp is pushed upwardly by the workman to the position shown by full lines in Fig. 5, whereupon the tension of the strap 15 is suflicient to cause the spike 17 h to enter the wood of the timber 14 and thus hold the clamp securely in place even though it be subjected to vibration during the usual building operations. When the standard sizes of the timbers 14 which are commonly employed in building operations for reenforcing the walls of the concrete forms and a limited number of sizes of this form of clamp are sufficient to take care of all ordinary requirements. It will be apparent that-this form of clamp embodies in one structure means for securing the strap thereto and for securing the clamp on the timber as well as being of such form that it serves as a tool for stretching the strap taut.

In Figs. 6, 7 and 8 of the drawings there is illustrated a modified form of the invention which is generally similar to the form described above except that the clamp is adapted to engage a side of thetimber lorated at right angles to the body portion of the clamp whereas in the first form, the side of the timber engaged by the spike is that opposite to the body portion or arm of the clamp to which the strap is applied. In the modified form, the clamp comprises a body portion or bar 20 having the upper end thereof revcrsely bent to form a flange or tongue 20 which is spaced from the body portion as shown at 20 to receive a strap of the usual thickness employed in this class of work. The upper bent portion 20 of the clamp is provided with a slot 20 adapted to be engaged by the strap which has its end reversely bent around the flange 20 to form an mterlocking engagement, as in the form of the invention previously described. The lower end of the bar 20 is provided with an integral flange 20 extending outwardly on the side thereof opposite the flange or tongue 20f at right angles to the plane of the body portion 20. This flange 20 is provided with a pair of upwardly extending sharpened spikes 20 which are adapted to engage the timber of the form to which the clamp is applied.

The method of using the clamp illustrated in Fig. 6 is shown in Figs. 7 and 8 where one wall 21 of aconcrete form is shown as being formed of a series of boards 22 secured to upright timbers 23 which have horizontal timbers 24 of rectangular cross sections secured to the outer edges thereof. A sheet metal strap 25 is employed for uniting the wall 21 with an opposite wall of the form and the wall 21 is provided with an aperture 26 through which the strap 25 passes in convenient relation to the upper surface of the timber 14. The end of the strap 25 is passed through the slot 20 of the clamp and through the space 2O after which the end thereof is reversely bent as shown at 25 to form an interlocking connection with the clamp. Assuming that the other end of the strap is secured on the outer side of the opposite wall of the form, the clamp 20 then occupies the inclined position shown in Fig. 7 with the inner surface thereof engaging the upper corner 24 of the horizontal timber 24. The operator then pushes downwardly and inwardly on the clamp until it assumes the po sition shown by dotted lines at 27 in Fig. 8. The clamp is then pushed upwardly to cause the spikes 2O to engage the underside of the timber 24 or, if desired, a hammer may be used to cause the spikes to firmly and securely engage the timber. In this form of the invention, also, the clamp serves as a stretching tool and embodies in itself means for holding the strap and for securing the clamp on the timber of the form.

In the accompanying drawings, both forms of the improved clamp have been shown applied to timbers extending horizontally but the clamps are applied in the same manner if the timbers 14 and 24 be regarded as vertical timbers. When the work is completed and the concrete has hardened, the clamps may readily be removed by bending the ends of the straps interlocked therewith and removing the spikes from the timbers. After the clamps have been removed, the walls of the form are taken down and the ends of the straps which project from the concrete wall are cut off in accordance with the practice heretofore followed with the use of other forms of clamps.

Although certain forms of the invention have been shown and described by way of illustration, it will be understood that it may be constructed in various embodiments within the scope of the appended claims.

I claim:

1. A concrete form clamp for use with a flexible metal strap projecting through the form, comprising a single metal bar adapted to rest against the outer surface of the form and having at one end means including a slot for forming a detachable interlocking connection with the strap and at the other end means including an integral spike for securing said bar to the form.

2. A concrete form clamp having means for securing a strap thereto, said clamp having a part adapted to serve as a lever to tighten the strap, and means for securing the clamp to the form after the strap has been tightened.

3. The combination with a concrete form comprising a wall having a timber projecting on the outer side thereof, of a concrete form clamp comprising a single metal bar adapted to rest against the outer surface of said timher, said bar having at one end means for forming a detachable interlocking connection with a flexible metal strap projecting through said wall adjacent one face of said timber, said bar having a part extending adjacent the face of said timber opposite said first-named face and carrying a spike adapt ed to enter said timber for holding said clamp in place.

4. A concrete form clamp having a slot at one end to receive a strap and form an inter-' locking connection therewith, and means at the other end of said clamp for engaging a supporting member to secure said clamp in position, the intermediate part of said clamp serving as a lever to tighten said strap be fore said clamp is secured.

A concrete form clamp comprising a bar having a reVers-ely bent flange spaced from said bar to form a space adapted to receive a strap, said bar being provided with a strap receiving slot at the juncture thereof with said flange, said bar being provided at the end thereof opposite said flange with a transversely extending part, and an integral spike carried by said transversely extending part.

6. A concrete form clamp comprising a bar having means at one end to form an interlocking connection with a strap, an arm formed.

integrally with said bar andextending transversely thereto at the end opposite said interlocking means, a flange extending from said arm parallel to said bar, and an integral spike carried by said flange and directed inwardly toward said bar.

7. A concrete form clamp comprising two right angularly disposed arms, one of said arms being provided at: one end With means for forming an interlocking connection With a strap, the other of said arms being provided at its end With an integral spike to engage a supporting timber.

8. A concrete form clamp comprising a bar reversely bent at one end to form a flange spaced from said bar, said bar and said flange being provided With a slot at the juncture thereof, an arm extending from said bar on the side thereof opposite said flange, said arm terminating in a part extending parallel to said bar, and a spike formed integrally With said part and extending inwardly therefrom toward said bar.

9. A concrete form clamp comprising a single member provided With a slot and a reversely bent flange at one end to form an interlocking engagement with a strap, and provided With an integral angularly disposed spike at the other end to engage a supporting timber.

In testimony whereof, I have subscribed my name. I

ALLEN B. lVILSON. 

